<template>
  <div class="score-case">
    <div class="table">
      <table>
        <thead>
          <tr>
            <th>编号</th>
            <th>科目</th>
            <th>成绩</th>
            <th>考试时间</th>
            <th>操作</th>
          </tr>
        </thead>
        <!-- 判断有没有数据 v-if v-else -->
        <tbody v-if="list.length">
          <tr v-for="(item, index) in list" :key="item.id">
            <td>{{ index + 1 }}</td>
            <td>{{ item.subject }}</td>
            <td :class="{ red: item.score < 60 }">{{ item.score }}</td>
            <!-- <td :class="item.score < 60 ? 'red' : ''">{{item.score}}</td> -->
            <td>{{ formateDate(item.date) }}</td>
            <td><a href="#" @click="delData(item.id)">删除</a></td>
          </tr>
        </tbody>
        <tbody v-else>
          <tr>
            <td colspan="5">
              <span class="none">暂无数据</span>
            </td>
          </tr>
        </tbody>
        <tfoot>
          <tr>
            <td colspan="5">
              <span>总分：{{totalScore}}</span>
              <span style="margin-left: 50px">平均分：{{ varScore}}</span>
            </td>
          </tr>
        </tfoot>
      </table>
    </div>
    <div class="form">
      <div class="form-item">
        <div class="label">科目：</div>
        <div class="input">
          <input type="text" placeholder="请输入科目" v-model.trim="subject" />
        </div>
      </div>
      <div class="form-item">
        <div class="label">分数：</div>
        <div class="input">
          <input type="text" placeholder="请输入分数" v-model.number="score" />
        </div>
      </div>
      <div class="form-item">
        <div class="label"></div>
        <div class="input">
          <button class="submit" @click="addData()">添加</button>
        </div>
      </div>
    </div>
  </div>
</template>

<script>
//引入moment包 先找 node_modules
import moment from 'moment';
export default {
  name: 'ScoreCase',
  data() {
    return {
      //获取本地数据 || 兜底用 给个[]
      list:JSON.parse(localStorage.getItem('list')) || [],
      subject: '',
      score: '',
    };
  },
  methods: {
    //删除
    delData(id) {
      //不是这个id的筛选出来
      this.list = this.list.filter((item) => item.id != id);
    },
    //添加
    addData() {
      if (this.subject && this.score) {
        if (this.score >= 0 && this.score < 100) {
          const obj = {
            id: this.list.length + 1,
            subject: this.subject,
            score: this.score,
            date: new Date(),
          };
          // this.list.push(obj)
          this.list = [...this.list, obj];

          //添加后清空input内容
          this.subject = '';
          this.score = '';
        } else {
          alert('请输入0-100的分数');
        }
      } else {
        alert('请输入正确的科目和成绩');
      }
    },
    //改时间
    formateDate(date) {
      return moment(date).format('YYYY-MM-DD HH:mm:ss');
    },
  },
  //计算属性 
  computed: {
    //总分
    totalScore() {
      return this.list.reduce((prev, item) => {
        return prev + item.score;
      }, 0);
    },
    //平均分    2/0除不了
    varScore(){
      return (this.list.length && this.totalScore / this.list.length).toFixed(2)
    }
  },
  //监听
  watch:{
    list:{
      deep:true,
      handler(value){
        //数据存本地
        localStorage.setItem('list',JSON.stringify(value))
      }
    }
  }
};
</script>

<style lang="less">
.score-case {
  width: 1000px;
  margin: 50px auto;
  display: flex;
  .table {
    flex: 4;
    table {
      width: 100%;
      border-spacing: 0;
      border-top: 1px solid #ccc;
      border-left: 1px solid #ccc;
      th {
        background: #f5f5f5;
      }
      tr:hover td {
        background: #f5f5f5;
      }
      td,
      th {
        border-bottom: 1px solid #ccc;
        border-right: 1px solid #ccc;
        text-align: center;
        padding: 10px;
        &.red {
          color: red;
        }
      }
    }
    .none {
      height: 100px;
      line-height: 100px;
      color: #999;
    }
  }
  .form {
    flex: 1;
    padding: 20px;
    .form-item {
      display: flex;
      margin-bottom: 20px;
      align-items: center;
    }
    .form-item .label {
      width: 60px;
      text-align: right;
      font-size: 14px;
    }
    .form-item .input {
      flex: 1;
    }
    .form-item input,
    .form-item select {
      appearance: none;
      outline: none;
      border: 1px solid #ccc;
      width: 200px;
      height: 40px;
      box-sizing: border-box;
      padding: 10px;
      color: #666;
    }
    .form-item input::placeholder {
      color: #666;
    }
    .form-item .cancel,
    .form-item .submit {
      appearance: none;
      outline: none;
      border: 1px solid #ccc;
      border-radius: 4px;
      padding: 4px 10px;
      margin-right: 10px;
      font-size: 12px;
      background: #ccc;
    }
    .form-item .submit {
      border-color: #069;
      background: #069;
      color: #fff;
    }
  }
}
</style>
